Taxonomy term

mass extinction

Mercury links Big Five extinction events

Mercury concentration spikes in the geologic record have been linked to massive volcanism in the form of large igneous provinces (LIP) such as the Deccan Traps, a kilometers-thick heap of basalt layers that formed in what is now India beginning late in the Cretaceous, and the Siberian Traps, an even larger mass of lava that erupted in Siberia at the end of the Per­mian. It’s thought that vast gas emissions associated with LIP eruptions could have significantly changed climate patterns and affected conditions such as ocean acidity. 

31 Aug 2018

Hot tropics drove out ancient reptiles, but they came back

About 252 million years ago, massive volcanic eruptions in what is now Siberia rapidly warmed Earth, resulting in the end-Permian mass extinction that saw most terrestrial and marine species die off. It’s been thought that surviving reptiles and fish fled the hot tropics and didn’t return for millions of years. But according to new research, the tropical evacuation may not have lasted so long after all.

21 Apr 2018

Volcanic activity contributed to first of the "Big Five" mass extinctions

During the Ordovician, between about 488 million and 444 million years ago, plant life first emerged on land, while primitive fish and a variety of marine invertebrates flourished in the oceans. Toward the end of the period, however, a mass extinction — the first of the so-called “Big Five” Phanerozoic extinctions — wiped out roughly 60 percent of all marine invertebrate genera. In a recent study, researchers shed new light on a possible cause of the Late Ordovician extinction: volcanic activity.

15 Nov 2017

Volcanism triggered end-Triassic extinction

The end-Triassic mass extinction exterminated up to three-quarters of all species on land and in the oceans 201 million years ago. This die-off opened up ecological niches and allowed for, among other changes, dinosaurs to diversify and spread across terrestrial ecosystems during the rest of the Mesozoic. Volcanism has long been implicated in the extinction, but whether it had a major impact on the planet at the time has remained unclear. In new research, scientists observed elevated mercury concentrations in extinction-aged rocks from around the world. Because volcanism is the main nonanthropogenic source of mercury in the environment, the findings suggest that volcanic activity was likely the main extinction trigger at the end of the Triassic.

21 Sep 2017

Hangover echinoderms survived the Great Dying

The end-Permian extinction event was disastrous for a wide range of organisms on land and in the sea, with as many as 70 percent of terrestrial and 81 percent of marine species dying off. One of the hardest hit marine phyla was the echinoderms, which today includes sea urchins and starfish. Echinoderms are thought to have suffered one of the most severe population reductions in evolutionary history, with only a few members surviving to repopulate the oceans in the Triassic. But in a new study, researchers have identified Triassic fossils from a handful of “hangover” species whose ancestors were previously thought to have gone extinct at the end of the Permian, suggesting the extinction wasn’t quite as cataclysmic for echinoderms as paleontologists have suspected.

12 Jul 2017

Geomedia: Books: Exploring "The Worst of Times"

Every reader of this magazine knows something about mass extinctions. But few of us know as much as Paul B. Wignall, a professor of paleoenvironments at the University of Leeds in England who studies mass extinctions. In 1997, he co-authored with Anthony Hallam a scholarly volume titled “Mass Extinctions and their Aftermath.” Now, his first book aimed at a popular audience, “The Worst of Times: How Life on Earth Survived Eighty Million Years of Extinctions,” has been issued in paperback.

02 Feb 2017

Downgrading the Great Dying

The end-Permian extinction, nicknamed the “Great Dying,” is thought to be the deadliest mass extinction in Earth’s history. Many textbooks claim that up to 96 percent of marine life died out during this event, but a new study suggests this cataclysmic number has been overestimated.
 

23 Jan 2017

Nutrient deficiency delayed life after mass extinction

After Earth’s most severe mass extinction, life took up to 9 million years to recover — millions of years longer than after other extinction events. New research published in Geology suggests that a collapse in the ocean’s productivity might have been the cause.

25 Nov 2016

Ancient plankton communities stressed before mass extinction

Changes in our modern ecosystems, such as declines in biodiversity and invasive species, are similar to those that preceded the first of Earth’s mass extinctions about 443 million years ago, according to a new study. Researchers recently found that ancient plankton communities began to show environmental stress nearly 400,000 years before the extinction, as the planet cooled.

15 Nov 2016

When Earth hit the reset button on life: New research on the Permian-Triassic mass extinction

The Permian-Triassic extinction 252 million years ago extinguished most life on Earth. Recent research weighs in on the kill mechanisms, the timing of the extinctions on land and in the water, and how the environmental degradation of the past may shed light on our current mass extinction.

25 Oct 2016

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